People with a limited or absent sense of sight require an alternate method for recognizing and navigating their physical environment. According to World Health Organization, 39 million people worldwide are legally blind and 246 million have low vision (www.who.int). Further, according to CDC, there are 3.4 million people in the United States who are either legally blind or substantially visually impaired (www.cdc.org). The rate of visual issues in the younger population has increased recently due to the blast-induced increase in Traumatic Brain Injury (TBI) associated with increased US military engagements, and TBI frequently produces visual impairments.
In the past, such people had to rely on other people, guide dogs, and canes for help in navigating environments. People helpers are rarely available, and guide dogs and canes provide only a limited amount of information to the blind person. Dogs can help guide a person around obstacles, or along a pre-trained route. Canes provide information on location of physical obstacles within immediate reach, but do not provide any information on the identity of such obstacles, or how to navigate around them. Blind people resort to guesses based on contextual interpretation of their assumed physical environment, i.e. I'm in a room and there is an object with a large flat surface and I feel empty space underneath—it could be a table.
Adaptive technologies based on various electronic approaches have been proposed and developed to provide solutions to the above identified problems. As a rule, they present information to the blind user through transforming environmental information into a usable sense, such as vibration, sound, or touch.
Some electronic devices use an emitted signal, such as an optical or an ultrasound pulse, and acquire a reflected signal. Examples are BuzzClip by Imerciv, which is worn like a button, or iGlasses by Maxiaids which are worn as glasses, and which use ultrasound to detect obstacles and alert wearer through vibration or audible tones (indiegogo.com/projects/the-buzzclip-wearable-mobility-tool-for-the-blind) (maxiaids.com/iglasses-ultrasonic-mobility-aid-clear-lensmaxiaids.com/iglasses-ultrasonic-mobility-aid-clear-lens). Similarly, optical ranging using laser sources is possible.
Another approach is to use GPS assistance to help blind people navigate predetermined routes. An example is Humanware's Trekker handheld GPS devices that provide verbal directions, information about nearby places of interest, public transportation information, etc.
Current technology is improving fast to assist disabled people, especially so with the proliferation of inexpensive and powerful smart phones. Specifically, assistive technology for blind people is evolving rapidly with the improvements in mobile devices such as smart phones and tablets and their embedded sensors. Smart assistants like Apple's VoiceOver provide an intuitive and convenient way for blind people to interact their mobile devices, access functions and interact with content. GPS and accelerometers provide information about mobile device relative position in space. High quality cameras provide high resolution images, both still and moving. Embedded processors allow sophisticated image processing algorithms to be run locally on the mobile device. High bandwidth network connections allow to offload functions that require more sophisticated and intensive processing to the cloud, and rapidly obtain processed results.
There are existing mobile device applications that provide assistive technology for blind people. LookTel by Ipplex recognizes and speaks the denomination of paper currency which is being captured by the camera. VizWiz by Rochci allows a user to send an image to sighted human volunteer along with a question, or to an automated engine for label identification. Color ID by GreenGar identifies colors of objects being captured by the camera. CamFind by CamFind and EyeSpy by My Eye Spy Pty identify some common objects in an image captured by the camera.
A common problem encountered by a blind person is understanding a new and unfamiliar environment, as for example when entering a room or space for the first time. A conventional approach for a blind person is to explore the walkable space with a cane, and use tactile feedback to identify objects. This is very time consuming, cumbersome, and potentially hazardous as the person can trip, bump into unexpected objects, touch dangerous surfaces such as a hot coffee maker or stove, etc. What is needed is a method for allowing a blind person to explore the space in a virtual environment, but with sufficient accuracy to be useful. Beneficially, such method would be based on an existing mobile device, such as iPhone, iPad, Android Phone and the like, that a user is likely to already own.